Aliases share the parameters of their parent (original) objects, but they also have their own, special parameters:
Reference pop-up menu: Use to select the original on which the alias is based.
Channel field: Rechannelizes all events (except fader events), leaving the alias to the selected channel. If the Channel setting is All, existing channelized events are not changed.
For faders, the Channel parameter causes the alias to act as if the original fader’s Input and Output definitions are both set to the specified channel. (An All setting results in no change.)
Share Name and Share Size: When selected, the alias shares the size and name of the original. If unselected, it can be resized and given its own name.